1. Field of the Invention
The invention relates to an inflatable or pneumatic float assembly for aircraft, particularly light and ultralight aircraft. Relative positions of the float and landing wheels of the aircraft can be changed so that the aircraft is amphibious.
2. Prior Art
Inflatable aircraft floats have been used on conventional light aircraft, one example being shown in U.S. Pat. No. 2,375,973 (Cooper et al). This patent discloses an inflatable float with internal transverse baffles in which a stiffening girder or boom is permanently fastened to either the inside or outside of the float upper wall, which results in a costly structure and one that cannot be folded into a small space for storage and shipping. Thus, while the float can be inflated it cannot be easily folded due to the relatively stiff girder which remains permanently attached to the float. Also, while this float is shown with a step, there appears to be no provision for stiffening the step to reduce deformation under load.
Most conventional amphibious aircraft have rigid metal floats, with a pocket therein which accept retractable landing wheels, thus permitting the aircraft to land on land, when the wheels are extended, or to land on water when the wheels are retracted. Such floats are heavy and costly, and the weight and complexity would be inappropriate for the relatively low power, simplicity and light weight associated with ultralight aircraft. While glass reinforced plastic floats have been used with ultralight aircraft, such floats tend to be relatively heavy and weak, and are clearly not collapsible for storage. Furthermore, most floats are not very resilient and this contributes to a rough ride on choppy water.
While most conventional amphibious light aircraft retract wheels into pockets in fixed floats, it is known to have fixed wheels in combination with movable floats that can be raised to permit the aircraft to use land or water. One example of this type of arrangement for an amphibious aircraft is shown in U.S. Pat. No. 3,159,364 (Sheaffer et al) in which laterally disposed pockets in the floats provide clearance for the wheels when the floats are in the lowered position. In most amphibious aircraft, mechanisms for raising and lowering the floats or wheels are relatively complex, and the pocket for the wheels introduces considerable complications in float design, and would be too costly and heavy for an ultralight aircraft.